Crispy puff pastry layers alternating with pastry cream is Italy's napoleon. This elegant mediterranean dessert is a family bakery tradition for special occasions.
Preheat your oven to 400°F. Line two baking sheets with parchment paper and lay out the thawed puff pastry sheets. Prick the sheets all over with a fork to minimize puffing.
Place another layer of parchment paper and a baking sheet on top of the pastry to weigh it down. Bake for 20–22 minutes until golden and crisp. Cool completely before assembly.
While the pastry cools, make the pastry cream: In a saucepan, heat whole milk over medium heat until just steaming—not boiling.
In a mixing bowl, vigorously whisk together egg yolks, sugar, flour, and salt until smooth. Temper by slowly streaming in half the hot milk with continuous whisking.
Return the mixture to the saucepan and cook over medium heat, stirring constantly, until it thickens to a custard (about 5–7 minutes); remove from heat and stir in vanilla extract. Let cool completely.
To assemble: Carefully slice or trim the baked pastry sheets into equal rectangles. Layer one pastry piece, spread with cooled pastry cream, then alternate layers, finishing with pastry on top.
Dust generously with powdered sugar before serving. Store in the refrigerator if not serving immediately.